Murky Red Hot water!

gunner0098

Hi folks,

We have moved into our house and have an unusual problem. When I turn on any hot taps, the water comes out a murky red colour. This lasts for about 20 - 30 seconds and then the water starts to clear. There is also a metallic smell present.
The H.W.S runs from a NIBE geothermal heat pump, connected to a horizontal ground source collector bed. There is an additional Grundfos 4 bar pump to pressurise the system.
Upon investigating the issue, I found that when I turn off the Grundfos pump, the murky red colour decreases greatly but the smell remains.
The geothermal guys came back and drained the cylinder (150 ltr) and said everything was fine with the equipment. My builder/plumber is blaming the geo system but can't offer a solution (no surprise there!!)
I have checked my tank in the attic and the water coming into the house is fine. Though, I did notice a fine layer of silt/sand on the bottom of the tank, but i think this might be normal (my builder concurred with this). Also I have an outside tap which runs directly from the mains and it is clear.

So, has anyone come across this before and have you any solutions? Any suggestions would be greatly appreciated.

muffler

You'll probably get a few replies in the DIY forum.

Moved

antoinolachtnai

I believe one possible explanation for this situation could be a mix of copper and metal pipes somewhere in your system. A metal tank with copper pipes perhaps?

What happens is electolysis, a bit like in a battery. the two different metals cause a tiny voltage through the water and result in copper being released into the water.

It is probably pretty harmless, unless you have some particular condition which makes you have a bad reaction to copper. Still, you should get it sorted out.

I'm afraid I can't give you a source on this. I really can't remember where I read about it. I have seen it happen, but I have never been in a position to get to the bottom of it.

There is a bit on the web at http://www.brisbane.qld.gov.au/BCC:BRISWATER::pc=PC_1397 - see the part about the galvanic reaction.

Of course, there could be other explanations.

Macy

We had the same problem, and it was Iron in the water. Well actually in our case it's iron and manganese. Happens frequently with the hot water tank, and also with the cold water tank in days like this. There's a bacteria that lives on the iron that gives the red colour, but it's only active at warmer temperatures - water from the mains/ well would be colder so hence it doesn't show up then.

We got one of the tests from www.acornwater.com , which came out with the high iron/ manganese readings (not really that surprising up in the mountains). Getting the actual filter is the next job, but it's a bit down the list at the moment - will be looking to source in the next few weeks. Ballpark is around €2000, with it being situated in a shed/ pumphouse with power and access to a drain/soak away.

Niether high iron or managanese are harmful, but they are a pain in the arse staining bathroom suites and tiles, and it obviously doesn't look very attractive.

Might be worth doing a test on the water and seeing what the story is - it might have nothing to do with the geothermal

gunner0098

I'm getting the water tested today. I'll post the results when I have them.

CJhaughey

Just on the off chance, do you have a pressure vessel/expansion vessel in your system?If so what colour is it?
I have had slightly rusty DHW since we moved in and recently it got worse, today I had a check from my solar installer and he said I had a leak from the expansion vessel, I had installed a red one in ignorance and it had corroded and made the water rusty, I replaced the vessel with a blue one (domestic water) and the problem seems to have been solved.
The red expansion tank is only for heating systems.
It may pay to spin your tank off and check it for corrosion.